Wire electric discharge machine that automatically corrects machining route according to corner angle

1. A wire electric discharge machine that creates a machining route based on an axial movement command of a machining program, corrects the created machining program, at a corner portion formed by two consecutive moving blocks within the created machining route, by extending an end point of a block to be machined first to form a new block, removing a portion extending from a start point of a block to be machined subsequently to an intermediate point to form another new block, and connecting the end point of the new block and the start point of the other new block by a straight line or an arc, and carries out discharge machining according to the corrected machining program, the wire electric discharge machine comprising: a corner angle acquiring unit that calculates a corner angle of the corner portion; and a machining route correcting unit that corrects the machining route according to the corner angle, wherein the machining route correcting unit sets, when the end point of the block to be machined first is extended, an extension distance of the end point as a correction distance a, and also sets a length of the portion to be removed extending from the start point of the block to be machined subsequently to the intermediate point as a return distance b, and corrects the machining route at the corner portion so that the larger the corner angle, the smaller any one of or both of the correction distance a and the return distance b.

7. The wire electric discharge machine according to claim 2 , wherein a constant determined for each of electrical machining conditions is used instead of the deflection amount of the wire electrode, and the offset amount is any one of a radius value of the wire electrode, a value obtained by adding the radius value of the wire electrode and a discharge gap, and the constant determined for each of the electrical machining conditions.